Elastic-fluid turbine.



C. A. SCHELLENS, ELASTIC FLUID TURBINE. APPLICATION FILED APR. 12. I916.

Patented Oct. 9, 1917.

Inventor,

Christopher #1. Schel lens, bL

CHRISTOPHER .A. SCHELLENS, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELASTIC-FLUID TURBINE.

Specification of Letters Patent.

Patented Oct. 9, 1917.

Application filed April 12, 1916. Serial No. 90,771.

To all whom. it may concern Be it known that I, CHRIs'roPHER A. SCHELLENS, a citizen of the Umted States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Im rovements in Elastic-Fluld Turbines, of W ich the following is a specification.

The present invention relates to elastic fluid turbines and especially to those of the so-called extraction type, meaning thereby a turbine from which steam is wlthdrawn or extracted from some intermediate stage and after it has given up a portion of its energy to the turbine rotor.

The object of my invention is to improve the construction of extraction turbineswhereby they may be made to operate more economically, and, if desired, with a higher extraction pressure than is commonly the case.

In carrying out my invention the turbine is divided into two parts,'tl1e first being provided with one or more stages to economically extract energy from the steam between boiler and extraction pressures, and the second with a suflicient number of stages to economically extract the energy of the steam between boiler and condenser pressures. The two parts of the turbine have a common casing and the rotors are mounted on the same shaft. Each part of the turbine has its own valve chest and valve or regulator, said regulators being primarily under the control of a speed governor driven by the shaft, and secondarily under the control of a device responsive to changes in pressure in the extraction conduit. As a result of this construction the use of a stage or extraction controlling valve at some intermediate part of the machine is avoided and the economy of the machine for dilferent conditions of operation is improved.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying specification and the claims appended thereto.

' In the accompanying drawing, Figure 1 is a side elevation of. an elastic fluid turbine, a portion of the casing being broken away to illustrate some of the parts in section; Fig. 2 is a diagrammatic view of the regulating mechanism, and Fig. 3 is a plan view of' the admission conduits and the valves arranged therein.

bers l0 and 11 by a diaphragm 12. In the chamber 10 is arranged one or more wheels designed to utilize high pressure motive fluid and from this chamber leads an extraction conduit 13 for supplying elastic fluid for industrial purposes. The wheel or ,Wheels in the chamber 10 are designed to utilize the elastic fluid from its initial pressure down to the pressure which is de sired for Industrial purposes. In the present instance a single wheel 14 having two rows of buckets is shown, but it will be understood that any suitable number may be utilized.- 15 indicates a valve mechanism for regulating the supply of elastic fluid to the turbine wheel 14, the elastic fluid being directed against the buckets by suitable nozzles as indicated at 16. The valve mechanism may be of any suitable type. In the present instance it is shown as being of the general nature of that shown in the patent to Richard H. Rice, No. 1,061,690, May

13, 1913, and it may be regulated through a suitable servo-motor as indicated at 17. The details of this motor are not shown as the operation is well understood and forms no part of the present invention. It will thus be seen-that the elastic fluid which is admitted by the valve mechanism 15 first acts upon the wheel or wheels 14, after which it exhausts through the extraction conduit 13. The portion of the turbine just described may be considered as constituting a high pressure non-condensing turbine sectlon.

In the chamber 11 is arranged one or more turbine wheels which are designed to utilize the elastic fluid from its initial pressure down to condenser pressure. In the present instance this chamber is shown as containing two stages which are separated from each other by the diaphragm 18. In the first stage is arranged a wheel 19 having two rows of buckets, .and in the second stage is arranged one or more wheels 20 each having a single row of buckets. It will be understood, of course, that any suitable number of wheels and stages may be provided. Elastic fluid from the second stage exhausts through a conduit 21 to a suitable condenser (not shown). High pressure elastic fluid is admitted to the chamber 11 by a suitable valve mechanism 22 which is preferably similar to the valve mechanism 15. 23 indicates the nozzles which direct the elastic fluid to the wheel 19 and 24 indicates nozzles in the diaphragm 18 for directing the elastic fluid to the wheel 20. The valve mechanism 22 is operated by a suitable servo-motor 25 similar to the motor 17 The turbine wheels arranged in the'chamber 11, it will be seen, utilize the elastic fluid from its initial pressure down to condenser pres sure and this may thus be termed a high pressure condensing section of the turbine. The valve mechanisms15 and 22 are regulated by means of a speed governor 26 and a pressure responsive device 27. The speed governor 26 may be of any usual or suitable type, 28 indicating the spindle thereof and 29 the governor lever. The pressure responsive device may comprise any suitable type of abutment which will move in response to In the present inchanges in pressure. stance, as shown in Fig. 2, it comprises a casing 30 in which is arranged a diaphragm 31. One side of the diaphragm is connected to the chamber 10 beyond the wheel 14 by the pipe 32. This side of the diaphragm is, therefore, subject to the extraction pressure in the chamber 10. The other side of the diaphragm is engaged by a spring 33, the tension of which may be adjusted by means of the nut 34. 35 indicates a spindle which is connected to the diaphragm 31, and through which movement is imparted from the diaphragm to the link 36, which is in I turn connected to arm 37 of a three-arm lever. The other two arms of the lever 38 and 39 are connected by rods 40 and 41 to the valve mechanisms 15 and 22 respectively. As shown in Fig. 1 this connection is through the servomotors 17 and 25. In the diagrammatic showing in Fig. 2, however, for the sake of simplicity, the servo-motors are omitted and the connection is shown as being direct. The governor lever 29 is connected to the three-arm lever by a link 42.

Referring to Fig. 3, 43 indicates a conduit through which elastic fluid is supplied to the turbine. It is provided with branches 44 and 45 in which are located the regulating valve mechanisms 15 and 22. and in which are also located the hand valves 46 and 47. 48 is a pipe which connects the extraction conduit 13 to the conduit 21 which leads to the condenser. In the pipe 48 is a valve 49. I

It will be seen that the structure comprises in substance two separate turbine sections contained in the same casing and mounted on a common shaft so as to dr1ve a common load, the section contained in the chamber 10 being a non-condensing section, while that contained in the chamber 11 is a condensing section.

In operation the valve 49 is closed and the spring 33 is designed and set to counterbalance the pressure which it is desired to maintain in the extraction conduit. High pressure fluid is then admitted through each of the regulating valve mechanisms 15 and 22 to the respective turbine sections. Referring to Fig. 2, particularly, it will be seenthat in case the speed tends to increase the right-hand end of the governor lever 29 willbe lowered, thus moving the valve mechanisms 15 and 22 toward closed position, and shutting 01f more or less the supply of elastic fluid to each of the turbine sections. On the other hand, if the speed tends to decrease, the right-hand end of the governor lever will be raised, thereby opening the regulating valve mechanisms 15 and 22 to admit more elastic fluid to each section of the turbine.

In case the pressure in the chamber 10 tends to decrease, indicating a diminution in the supply of extraction fluid available, then the diaphragm 31 will move toward the left due to the action of the spring 33. This will swing the arm 37 toward the left and tilt the three-arm lever, the same pivoting on the link 42. This movement will further open the valve mechanism 15, thus increasing the supply of elastic fluid to the non-condensing section of the turbine and will further close the valve mechanism 22, thus decreasing the supply to the condensing section of the turbine. This means that the non-condensing section will take more ofv the load, the supply of elastic fluid for extraction purposes being at the same time increased, while the condensing section will lose part of its load. Sufficient elastic fluid is thus supplied to the non-condensing section to keep up the'supply for the extraction conduit. In case the pressure in the chamber 10 tends to increase, thus indicating an excess of elastic fluid for extraction purposes, then the diaphragm 31 is moved to the right, thus tilting the three-arm lever in the opposite direction to that already referred to. This will shut off more or less the supply of elastic fluid to the non-condensing section, and increase the supply of the condensing section. This will cause a diminution in the supply of elastic fluid available for extraction purposes, and at the same time some of the load will be shifted from the non-condensing section to the condensingsection. From this it will be seen of the condenser, thus materially reducing,

the rotation losses of the wheel'or wheels 14 which will be running idle.

On the other hand, in case the load bears such a relation to the demand for elastic fluid for industrial purposes that the extraction conduit will require all the elastic fluid that the non-condensing section will take in carrying the load, then the condensing section will run idle, the supply of elastic fluid to it, of course, being then automatically cut off by the valve mechanism.

By the above described arrangement I provide a machine which is very eificient under all conditions of operation. When operating as an extraction machine the regulating mechanism operates automatically to admit only suflicient elastic fluid to the non-condensing section as is required at any time to supply the demand for industrial purposes, the remaining portion of the elastic fluid required to carry the load being efliciently utilized in the condensing section, and when operating without extraction, all the elastic fluid required to carry the load is efiiciently utilized in the condensing section, the wheels of the non-condensing section then running idle in a vacuum. Furthermore, by this arrangement I avoid the use of a stage or extraction controlling valve, the elastic fluid being controlled in each instance by a high pressure valve mechanism which may of course be bal anced. This is of particular advantage in case of high extraction pressures.

In accordance with the provisions of the 1 patent statutes, I have described the prin ciple of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means. 7

What I claim as new and desire to secure by Letters Patent of the United States, is

1. In an elastic fluid turbine, the combination of a high pressure non-condensing section, a high pressure condensing section, an extraction conduit connected with the noncondensing section and into which it exhausts,

. a 'valve mechanism foradmitting elastic fluid to the non-condensing section, a valve -mechanism for admitting elastic fluid to the condensing section, a speed governor connected to said valve mechanisms, and a pressure responsive'device acting on said valve mechanisms simultaneously and in theopposite sense.

2. In an elastic fluid turbine, the combi-- nation of a high pressure non-condensing section, a high pressure condensing section, an extraction conduit connected with the non-condensing section and into which it exhausts, a valve mechanism for admitting elastic fluid to the non-condensing section, a valve mechanism for admitting elastic fluidto the condensing section, a speed governor connected to said valve mechanisms, and 'a pressure responsive device also connected to them, said speed governor acting on said valve mechanisms in the same sense, and said pressure responsive device acting on them in the opposite sense.

I 3. In an elastic fluid turbine, the combination of a casing, a diaphragm dividing it into two separate chambers, wheels in each such chamber passes, an exhaust conduit connected to the other chamber, a governor for regulating the valve mechanism in accordance with the load, and a pressure device responsive to the extraction pressure for limiting the amount of elastic fluid 'ad-- mitted to the one chamber to that which is required for extraction purposes, said governor acting on the valve mechanisms. in the same sense, and the said pressure responsive device'acting on them in the opposite sense. In witness whereof, I hereunto set my hand this tenth day of April, 1916.

CHRISTOPHER A. SOHELLENS. 

